This invention relates in general to data communication, and more particularly to determining the data rate capacity of digital subscriber lines.
Traditional telephone networks are designed to provide voice transmissions, and performs this function well. In general, however, the existing telephone networks are not adept at high speed data transmission. Digital Subscriber Line technology (DSL) uses existing twisted pair telephone lines to transport high bandwidth data, such as multimedia, video on demand, and Internet access, to data service subscribers. DSL technology uses a DSL transceiver unit (e.g. modems, splitters, and other communication equipment) at the central office of the data services provider and at the subscriber premises to utilize a greater range of frequencies of the telephone line than traditional telephone services, resulting in high speed data transmission.
To receive data services, therefore, a subscriber must install the proper communication equipment at the subscriber premises to support transmitting and receiving data using DSL technology over the existing telephone lines. Under certain circumstances, even a subscriber having the proper communication equipment may be unable to receive data services using particular DSL technologies. Since the communication equipment required at the subscriber premises may be expensive and the quality of data services received is uncertain, a potential data services subscriber may request from the data services provider an estimate of the data rate capacity of the telephone line servicing the potential subscriber before installing the communication equipment.
The data rate capacity of an existing telephone line generally defines the maximum throughput of the telephone line and typically depends on a number of factors. For example, the data rate capacity of a particular telephone line depends on the length of the telephone line, the gauge of wiring used in the telephone line, and the number and type of noise or interference producing elements present near the telephone line. A typical telephone line may be arranged in one or more binder group segments. In general, a binder group segment comprises a collection of telephone lines that share a common sheath. Each of the factors which affects the data rate capacity of a particular telephone line may vary among the different binder group segments of that telephone line. In addition, the provisioning of data services to a subscriber premises over a telephone line in a particular binder group may contribute to the noise and distortion upon other telephone lines within the same binder group, thereby degrading the services already provided to other subscriber premises.
Due to the number of factors affecting the data rate capacity of a particular telephone line, data services providers often cannot provide an accurate estimate of the data rate capacity to a potential subscriber. In some cases, a data services provider may perform a xe2x80x9ctruck rollxe2x80x9dxe2x80x94the dispatch of a service technician to install communication equipment or to configure the telephone line at the customer premisesxe2x80x94to determine the-data rate capacity of a particular telephone line. A truck roll, however, is time consuming and cost prohibitive for the data services provider and the subscriber.
In accordance with the present invention, a system for determining the data rate capacity of digital subscriber lines is provided which substantially eliminates or reduces disadvantages and problems associated with previous communication systems.
In accordance with one embodiment of the present invention, a system for determining the data rate capacity of a twisted pair subscriber line includes a communication server coupled to a number of subscribers using a number of subscriber lines. The system includes a memory coupled to the communication server that stores attenuation information and noise information for the subscriber lines. A processor coupled to the memory determines the data rate capacity of a selected subscriber line using the attenuation information and the noise information.
Another embodiment of the present invention is a method for determining the data rate capacity of a twisted pair subscriber line. The method includes storing attenuation information and noise information for a number of twisted pair subscriber lines that couple a number of subscribers to a communication server. The method concludes by determining the data rate capacity of a selected subscriber line using the attenuation information and the noise information.
Technical advantages of the present invention include a system for determining the data rate capacity of a twisted pair subscriber line that includes a communication server, a memory, and a processor. The memory stores attenuation information, noise information, or any other subscriber line information for a plurality of subscriber lines. The processor determines the data rate capacity of a selected subscriber line using the attenuation information and the noise information. In this respect, a data services provider in the system may pre-provision data rates for the subscriber line of a subscriber prior to activating data services for the communication equipment at the subscriber premises.
An important advantage of the system is that the communication server includes one or more communication devices that support determining subscriber line information while providing data services to subscribers during operation. The processor collects the subscriber line information from the communication server for storage in the memory. In this respect, the processor may collect subscriber line information from a number of communication servers in the system.
Another advantage of the system is that the memory can store attenuation information for a particular subscriber line based upon the constituent binder group segments of the subscriber line. The processor may then determine the attenuation information of a selected subscriber line according to the attenuation characteristics contributed by each of its constituent binder group segments. In this respect, the system may more accurately determine the data rate capacity of a selected subscriber line.
Another advantage of the present invention is a system for determining the transmit power of a communication device operating on a subscriber line of the system. The system includes a communication server having a communication device that operates on the subscriber line, a memory, and a processor. The memory stores noise information and cross-channel-coupling information for a plurality of subscriber lines in the system. The processor determines the transmit power of the communication device based upon the noise information and the cross-channel-coupling information. By determining the optimal transmit power of a communication device, the system may provide data services to a subscriber that does not degrade the data services provided to other subscribers.
A further advantage provided by the present invention is that the system may select a communication protocol for the communication device that is best adapted to provided the determined transmit power spectrum. In some instances when the communication device is inoperable to communicate data using a first communication protocol, such as an xDSL communication protocol, the system may operate the communication device using an alternative communication protocol, such as a V-series communication protocol. In this respect, a subscriber of the system is less likely to suffer a loss of data services.